/* 
 *	Copyright (C) 2009-2010 miaohua
 *	http://code.google.com/p/lrcshower/
 *
 *  This Program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2, or (at your option)
 *  any later version.
 *   
 *  This Program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 *  GNU General Public License for more details.
 *   
 *  You should have received a copy of the GNU General Public License
 *  along with GNU Make; see the file COPYING.  If not, write to
 *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. 
 *  http://www.gnu.org/copyleft/gpl.html
 *
 */

#pragma once


#include <memory>
#include <Windows.h>
#include <Wininet.h>
#include "DownloaderInterface.h"

// Simple file downloader
// Single thread
// Can download to local disk or memory
class CSimpleFileDownloader: public IFileDownloader
{
public:
     // the constructor will throw exception if it fails to init internet
     CSimpleFileDownloader();
     virtual ~CSimpleFileDownloader();

     // Download the appointed url html file, and save it to local file(fileFullPath)
     // the parameter "Param" can be : 
     // 1. [in]    full path of the local file(save to disk)
     // 2. [out]  string contains the content of the file(save to memory)
     virtual bool StartFileDownload(const tstring & Url, tstring & Param);
     virtual bool StopFileDownload();

private:
     // Get the internet web session
     HINTERNET GetSession(const tstring &URL);
     // Helper function to do the actual work
     bool Download(HINTERNET hSession, tstring & FileFullPath);
     // Download the file to harddisk file
     bool Download2File(HINTERNET hSession, const tstring & localFile);  
     // Download the file to memory cache
     bool Download2Mem(HINTERNET hSession, tstring & MemFile);
     // Get memory cache pointer
     bool GetPageCache();

     HINTERNET m_Internet;                       // Internet access handler
     std::auto_ptr<char> m_PageCache;            // Memory cache
     static const int m_CacheSize;               // Size of memory cache
};